counter_cache validation fails with Rails 7.2.beta

### Description

Testing counter_cache no longer works with Rails 7.2.beta.

### Reproduction Steps

Define an association like this:
```ruby
belongs_to :company, optional: true, counter_cache: true
```

The following test will fail:

```ruby
it { is_expected.to belong_to(:company).optional.counter_cache(true) }
```
### System configuration

shoulda-matchers (6.2.0)
